Simulation – Laser Processes and Systems

Simulation and modeling tools can be used to optimize a large number of laser applications, or even to build them in the first place. In this area, Fraunhofer ILT develops solutions, among other things, for specific designs of optics and free-form surfaces, laser beam profiles or scanning strategies for manufacturing products with tailored quality.

The spectrum ranges from laser-based cutting and welding to drilling and structuring to additive laser manufacturing processes. Simulation aims to help better understand the processes involved, to increase productivity and quality, and reduce costs and resources. To reach such goals, the institute uses numerical tools and methods of model reduction or meta-modeling as well as multi-scale simulations, among others. The software solutions it has developed are suitable for process simulations when metals, semiconducting materials, glasses, ceramics and plastics are applied.

We focus on the reduction of models to the specific application, which allows their use as a link between machine and production environment. Within the context of the Fourth Industrial Revolution and cyber-physical systems, digital images – of machines or processes, for example – are becoming increasingly important. We also research artificial intelligence methods, with which simulations can be calibrated from the data obtained, the condition of machines analyzed, or errors in the production process detected and corrected. Here, too, modeling or simulations are used to increase quality, efficiency and robustness.

In addition to individual consulting, the range of services we offer includes the development of application-specific, digital solutions and their integration into a production environment. 

Applications

• Concepts for guiding laser manufacturing processes
• Design of high power laser systems

Process and Component Development

• Optics, beam guidance and beam shaping
• Heat conduction and thermomechanics
• Phase transitions such as melting, solidification, evaporation
• Fluid dynamics of the melt
• Simulation of gas flows and nozzle design

Analysis

• Beam diagnostics, process monitoring and diagnostics
• Image processing and analysis of experimental data

Process Quality

• Process window and process limits
• Process stability
• Quality from melt
  • Scoring, roughness and dross during cutting
  • Low distortion welding with defined welding depth
  • Low-distortion additive manufacturing
  • Delamination and cracking
• Damage mechanisms - electronic, thermal, mechanical

Simulation

• Dynamic process simulation
• Efficient numerical methods - from laser spot to component
• Process optimization
  • Solving inverse tasks with neural networks
  • Combination of machine learning (ML) with simulation
  • Metamodeling – process maps
• Digital hybrid connection – non-metal with metal
• Ultra-short pulse structuring and separating – first time right – scan strategy
  • Metal
  • Glass and low-Ƙ materials 
  • Semiconducting surface layers
• In-house high-performance computer cluster
  Computational steering

Aden, M.:
Influence of the laser-beam distribution on the seam dimensions for laser-transmission welding:
A simulative approach
Lasers Manuf. Mater. Process, Online first (11 S.) (2016)

Bürgermeister, L., Hermann, M., Fehér, K., Molano Lopez, C., Pich, A., Hannen, J., Vogt, F., Schulz, W.:
Modelling pH-optimized degradation of microgel-functionalized polyesters
J. Healthcare Eng. 2016 (8 S.) (2016)

Sun, M., Eppelt, U., Hartmann, C., Schulz, W., Zhu, J., Lin, Z.:
Damage morphology and mechanism in ablation cutting of thin glass sheets with picosecond pulsed lasers
Opt. & Laser Technol. 80, 227-236 (2016)

Eppelt, U., Al Khawli, T.:
Metamodeling of laser cutting
AIP Conference Proceedings 1648, S. 710002 (2015)

Hermanns, T., Thombansen, U., Stoyanov, S.:
Modelling for self-optimization in laser cutting
AIP Conference Proceedings 1648, 710003  (2015)

Sun, M., Eppelt, U., Schulz, W., Zhu, J.:
Mechanism of internal modification in bulk borosilicate glass with picosecond laser pulses at high repitition rates
Proc. SPIE 9532, 953214 (13 S.) (2015)

Bürgermeister, L., Romero López, F. , Schulz, W.:
Physical and mathematical modeling of antimicrobial photodynamic therapy
J. Biomed. Opt. 19, 071411 (10 S.) (2014)

Reinhard, R., Al Khawli, T., Eppelt, U., Meisen, T., Schilberg, D., Schulz, W., Jeschke, S.:
The contribution of virtual production intelligence to laser cutting planning processes
In: Enabling Manufacturing Competitiveness and Economic Sustainability, Proc. of the 5th International Conference on Changeable, Agile, Reconfigurable and Virtual production (CARV2013), October 6th - 9th 2013, Munich, 117-124 (2013)

Reinhard, R., Eppelt, U., Al-Khawly, T., Meisen, T., Schilberg, D., Schulz, W., Jeschke, S.:
How virtual production intelligence can improve laser-cutting planning processes
22nd International Conference on Production Research, ICPR 2013. July 28th - August 1st, 2013, Iguassu Falls, Brazil. Iguassu Falls (7 S.) (2013)

Sun, M., Eppelt, U., Russ, S., Hartmann, C., Siebert, C., Zhu, J., Schulz, W.:
Numerical analysis of laser ablation and damage in glass with multiple picosecond laser pulses
Opt. Expr. 21, 7858-7867 (2013)

Sun, M., Eppelt, U., Schulz, W., Zhu, J.:
Role of thermal ionization in internal modification of bulk borosilicate glass with picosecond laser pulses at high repetition rates
Opt. Mat. Expr. 3, 1716-1726 (2013)

Thombansen, U., Purrio, M., Buchholz, G., Hermanns, T., Molitor, T., Willms, K., Schulz, W., Reisgen, U.:
Measurement of process variables in melt based manufacturing processes
In: ISMTII 2013 - The 11th International Symposium on Measurement Technology and Intelligent Instruments
Aachen /Braunschweig July 1st-5th 2013 (6 S.) (2013)

Vossen, G., Hermanns, T., Schüttler, J.:
Analysis and optimal control for free melt flow boundaries in laser cutting with distributed radiation
ZAMM Zs. Angew. Math. Mech. (Early view) 20 S. (2013)

Bürgermeister, L., Mikalauskaite, R., Vossen, G., Schulz, W.:
Antimikrobielle Photodynamische Therapie - Analyse des Ablaufs der chemischen Prozesse
Automatisierungstechnische Verfahren für die Medizin
10. Workshop 29./30. März 2012, pp.13-14, (2012)

Thombansen, U., Beckers, M., Buchholz, G., Hermanns, T., Molitor, T.,
Willms, K., Reisgen, U., Schulz, W.:
Signal processing for self-optimising manufacturing systems in
laser-cutting and gas-metal-arc-welding
1st Joint International Symposium on System-Integrated
Intelligence, 114-116, (2012)

Poprawe, R., Schulz, W., Schmitt, R.:
Hydrodynamics of material removal by melt expulsion: Perspectives of laser cutting and drilling
Physics Procedia 5, Nr 1,1-18, 2010

Schulz, W., Nießen, M., Vossen, G., Schüttler, J.:
Modelling and process monitoring of laser processing
Fraunhofer Allianz Numerische Simulation NUSIM: 1. Int. Conf. Multiphysics Simulation - Advanced Methods for Industrial Engineering June 22-23, 2010 in Bonn, 19 S., (2010)

Schulz, W., Pfeiffer, S., Zäh, M., Föckerer, T., Schober, A.:
Untersuchung der strukturellen Stabilität von Modellen zur Schweißverzugssimulation bei Stahlwerkstoffen
Forschungsbericht FOSTA, Forschung für die Praxis P 708, 2010. 71 S. ISBN 3-937567-77-1

Vossen, G., Schüttler, J., Nießen, M.:
Optimization of partial differential equations for minimizing the roughness of laser cutting surfaces
In: Diehl, M., Glineur, F., Jarlebring, E., Michiels, W. (Eds.): Recent Advances in Optimization and its Applications in Engineering. Berlin, Heidelberg: Springer, pp. 521-530. ISBN 978-3-642-12598-0, (2010)

W. Schulz, U. Eppelt:
Basic concepts of laser drilling
In: The Theory of Laser Materials Processing: Heat and Mass Transfer in Modern Technology. Ed. J. M. Dowden
Dordrecht: Springer Series in Materials Science, Vol. 119
pp. 129-165, (2009)

J. Schüttler, J. Lose, R. Schmitt, W. Schulz:
Exploring processing domain boundaries of complex production processes using a metamodeling approach
12th CIRP Conf. on Modelling of Machining Operations, May 7-8, 2009, San Sebastian (Spain). Ed.: P.J. Arrazola. Vol. 2
Paris: CIRP 2009, pp. 835-841, (2009)

W. Schulz, M. Nießen, U. Eppelt, K. Kowalick:
Simulation of laser cutting
In: The Theory of Laser Materials Processing: Heat and Mass Transfer in Modern Technology. Ed. J. M. Dowden
Dordrecht: Springer Series in Materials Science, Vol. 119
pp. 21-69, (2009)

N. Pirch, K. Wissenbach:
Mechanisms during laser bending
J. Laser Appl. 20, Nr 3, 135-139, (2008)

Our services cover a wide range of topics. Related topics to simulation and further research and development focuses can be found under the following links.